LHD and RHD rack housings

For those wanting to convert an MGA from Left Hand Drive to Right Hand Drive (or vice versa), the steering rack assembly is a mirror image, but in fact only two parts are different. One piece of the housing weldment holding the guide for the pinion shaft is a mirror image. Once welded together this makes the entire rack housing a mirror image. The pinion gear has different helix angle on the teeth as it meshes at different angle to the straight teeth on the gear rack. All the rest of the steering rack assembly is same parts for LHD or RHD. If you can find the mirror image rack housing, and buy the correct matching pinion gear, you can reassemble it with other parts from the old assembly to change from LHD to RHD (or vice versa).

Housing and gear rack lengths


Housing Pinion ends - Housing common end - End casting numbers
(Photos from Dennis Suski, Pasadena, MD, USA)

LHD - Pinion gears - RHD

RHD pinion end

Casting numbers on the rack housing end pieces are:
      16147U - On common end
      16148U - RHD Pinion end
      16149U - LHD Pinion end

The pipe in between the housing end pieces is a plain steel pipe cut to length (wall thickness unknown). The end pieces are stitch welded in place (not continuous welds). The housing holds oil and does not leak in assembly, so there must be some sort of seal between the housing ends and the pipe. If you were to "re-fabricate" a housing by replacing an end piece, you might continuous weld the joints, but be very careful not to thermally distort the assembly as the end pieces must be coaxial to carry the sliding gear rack.

Lubricator fittings ("Zerk" fittings) are a little different between LHD and RHD. LHD uses a straight Zerk on top of the Pinion shaft journal and a 45 degree Zerk on top of the main housing. RHD uses two 45 degree Zerk fittings. Steering racks for the Twin Cam (but maybe not the "Deluxe") are different again, putting the Zerk fittings on the bottom. Lubrication calls for 6-ounces of gear oil in the rack housing and a couple shots of grease for the pinion shaft input journal.

Addendum December 1, 2023:
SR205 talks about splitting the rack and a possible seal. I’ve done this and didn’t find a seal, however, as shown in the attached picture, the center tube is inserted some distance into the end knuckle and is quite tight. I made a spreading tool to split the two pieces after removing the three welds.

For complete steering rack rebuild and assembly see article SR-201.
For the rest of the LHD to RHD conversion process see CF-201 in the Care and Feeding section.